Background. Adherence to adjuvant hormonal therapy for patients with hormone-dependent HER2-negative breast cancer is of fundamental importance and affects the treatment outcomes.
Objective. Assessment of the adherence to AHT among patients with hormone-dependent HER2-negative breast cancer after radical treatment, as well as possible reasons for its decline.
Methods. In order to study compliance, we initiated a survey among patients with luminal HER2-negative breast cancer who were receiving or had previously received adjuvant hormonal therapy. The study involved 420 patients. 64.5% of patients took the drug without fail, and 19% of patients occasionally (up to 5 times a month) missed doses. A decrease in compliance was noted with an increase in the duration of therapy. The most common reasons for interrupting therapy before the prescribed time were adverse events (10%), lack of the drug in the pharmacy (10%), forgetfulness (5%), and some patients did not consider it necessary to take the prescribed drugs (2.4%). Every second patient did not have the necessary amount of information about the treatment.
Results. The results of the study emphasize the need to develop solutions to inform patients about the importance of therapy, the risks associated with refusing treatment, as well as side effects and ways to correct them. Such tools will increase patient adherence to therapy, and therefore improve treatment results and reduce the likelihood of relapse.

Keywords: adjuvant hormonal therapy, survey, breast cancer, compliance